1. Field of the Invention
The invention relates in general to a stamp device and a process for wafer bond, and more particularly to a recyclable stamp device and a recyclable stamp process for wafer bond.
2. Description of the Related Art
The wafer bond process is widely applied to all kinds of fields, such as micro electro mechanical system (MEMS) manufacturing process and the manufacture of optoelectronic elements. The wafer bond process, which is performed before the wafer saw process, is a wafer-level bonding technology, so the wafer bond process is different from other packaging methods which perform the wafer saw process before the bonding process.
Accurate alignment is needed before the wafer bond process is performed, so that the wafers can be bonded at the precise location. Traditionally, the alignment is performed through an alignment mark which is a concave structure formed by etching. However, the etching rate of etching the substrate is affected by the crystallization direction of the substrate, so that the alignment mark is deformed. As a result, the alignment accuracy is lowered.
Furthermore, the alignment mark is usually worn out or disappears as the manufacturing process proceeds. If the wafer with the alignment worn out or disappearing is utilized again to perform the wafer bond process, another alignment mark or another wafer is needed, so that the time and the cost of the manufacturing process are increased.